You should have received a W2G, not a 1099-Misc, if you had gambling winnings and not worked for the Casino. Please contact the Casino and ask them to issue you the correct form. They have to send you and the IRS the correct form.
However, Casinos issue 1099-Misc for gifts, reward points, etc for high rollers. If this situation applies to you then you would receive a 1099-Misc from the Casino.
[Edited 2/6/18 9:04 AM PST]